1. Field of the Invention
The invention is related to a device for distributing the pressure of a ski, such as especially an alpine ski, over its gliding surface.
The ski is also related to an assembly of front and rear binding elements for alpine skis, as well as an alpine ski, equipped with such a device.
2. Description of Background and Relevant Information
Skis that are used for alpine skiing are constituted by relatively long beams, on which the boots of the skier are retained by front and rear binding elements. The boot and the binding elements are located approximately in the median zone of the ski, which is commonly known as the middle sole. When at rest, the skis exhibit a natural arch, whereby the blade is naturally raised with respect to the front end of the ski, or shovel, and the rear end of the ski, or tail. In addition, the skis have a flexibility that depends on their internal structure. While skiing, the ski is elastically deformed in response to the various forces to which it is subjected by the skier, as well as by the terrain over which it glides.
The foremost stress to which a ski is subjected is constituted by the weight of the skier and the reaction to which the gliding surface subjects the ski.
The ski is also biased by the binding elements. Indeed, it is known that the binding elements pinch the boot along a longitudinal direction. The reaction to this pinching action is transmitted by the binding elements to the ski. However, this reaction differs depending on the assembly mode of the rear binding element to the ski. In fact, some binding elements are assembled directly onto the ski, whereas others are assembled to the front binding element by an inextensible link, such as a metallic blade that extends beneath the boot.
The ski is also influenced by the position of the skier above his or her boots, depending on whether the skier carries his or her weight towards the front or towards the rear.
It is known that the behavior of the ski on the snow can be modified, especially its ease of turn initiation, its operational quality in turns or in a straight line, by influencing the camber of the ski, or by varying the longitudinal pressure distribution of the ski on the snow. It is known that the ski can be rendered more or less pivoting, or more or less guiding, by varying this pressure distribution, i.e., one can promote its ability to take turns easily, and its ability to manifest substantial operational stability. For skis that are currently on the market, the pressure distribution of the ski on the snow is mainly determined by the internal structure of the ski and by the assembly mode of the binding elements to the ski, i.e., with or without a connecting blade between the front and rear binding elements. Pressure distribution can also be influenced by the intensity of thrust provided to the return springs that determines the pinching of the boot between its binding elements.
There are devices with attached elements that enable the pressure distribution of the ski on snow to be modified. As such, European patent application No. 183,586 describes a blade made of an elastic material of the spring blade type attached above the ski, between the binding elements and the ski. This blade has cursors in the area of its front and rear ends, whereby a portion of the stresses to which the ski is subjected is transmitted vertically. However, this device has the disadvantage of mediocre performance with substantial space requirements. It is adapted for the case where both feet of the skier are in support on the same ski, in order to avoid the entire weight of the skier from being concentrated in the middle sole zone. On the other hand, it is ill-adapted in the case of a pair of conventional skis.
European patent application No. 409,749 discloses a device constituted by a plate which is raised with respect to the upper surface of the ski, maintained between two longitudinal abutments. Elastic shock absorption means are inserted between the plate and the abutments and the pre-stress exerted on these elastic means is adjustable. As for the bindings, they are mounted on the plate. This device provides good results, but its disadvantage lies in the fact that the binding elements are affixed to the attached plate and not to the ski itself. Other devices of the same type are described, for example, in the U.S. Pat. No. 2,560,693, and the German patent No. 22 59 375.
It should be noted that the influence exerted by these devices on the flexion of the ski is of the static type, i.e., they do not take into account the position of the skier on the skis while gliding.